1. Technical Field
The present invention generally relates to motor vehicles. More particularly, the present invention relates to a method and apparatus for absorbing impact energy during an impact collision of a motor vehicle.
2. Discussion
Federal Motor Vehicle Safety Standard (FMVSS 201) requirements scheduled for gradual introduction beginning with the 1999 model year specify maximum HIC (head injury criteria) for various points in the upper portions in the vehicle interior. In testing, the head of an anthropomorphic test device (ATD or test dummy) is impacted with the vehicle interior at a predetermined speed at each of the designated points. The HIC from the impact is derived with data obtained from a tri-axial accelerometer located on the ATD head.
Various arrangements have been proposed for absorbing energy at different impact points above the belt line. For example, commonly assigned U.S. Ser. No. 08/963,750, filed Nov. 4, 1997, discloses an apparatus for attaching a seat belt to a B-pillar which is capable of absorbing energy in the event the vehicle is involved in a side impact collision. The apparatus includes an anchorage assembly attached to a mounting plate. A D-ring is attached to the anchorage assembly and is operative for receiving a shoulder belt portion of the seat belt webbing. The anchorage assembly is preferably attached to the mounting plate at attachment points which are spaced apart on the mounting plate and are adapted to displace in an outboard direction when the anchorage assembly is subjected to a predetermined compression load. U.S. Ser. No. 08/963,750 is hereby incorporated by reference as if fully set forth herein.
It is also known to absorb impact energy within a vehicle occupant compartment through the addition of foam, such as polystyrene or the like. One such example is shown in commonly assigned U.S. Pat. No. 5,709,407, which is hereby incorporated by reference as if fully set forth herein. While often desirable for certain applications, foam energy absorbers are associated with disadvantages. For example, foam energy absorbers are relatively thick and necessarily intrude into the vehicle interior.
Thus, it is desirable to provide an improved apparatus for absorbing impact energy at interior points within a motor vehicle.